MOLECULAR ANALYSIS OF THE BACTERIAL FLAGELLAR MOTOR

描述：该提案寻求对最小生物的理解 已知的马达，细菌鞭毛马达，它广泛存在于 真细菌和古生菌。该马达有几个不同的特点： (I)它是由跨膜质子势驱动的，而不是由ATP驱动的；。(Ii)它 经历真正的旋转；(Iii)它可以逆时针旋转 和顺时针方向，即它有一个开关；以及(Iv)该开关是 由感觉转导系统控制以实现趋化作用。因此， 该系统允许探索几个基本的生物学问题，例如 感官接收和转导，受控的分子开关，以及 机电和渗透机械能量传递。建议数 将在鼠伤寒沙门氏菌中进行的研究是其 大自然。 然而，它已经提供和将提供的信息已经被 其他研究工作在更多的应用领域，其中运动的作用 以及人类(和其他)微生物病原体毒力的趋同性 包括植物在内的寄主)和环境生态学(包括在陆地和在 (海洋)正在积极调查中。 该提案大量使用了突变(自发的和工程的)和 或基因间抑制，在组成马达的五种蛋白质中。 它们是MOTA、MOTB、FLIG、FLIM和FLIN。它将建立在现有基础上 关于这些蛋白质的知识，以期准确识别 (I)质子输送到现场的最关键区域和残留物 扭矩产生(MOTA和MOTB)；(2)扭矩产生本身( MOTA-FliG接口)；开关接收感觉信息( Chey-Flim界面)；以及(Iv)使用该信息来切换电机 方向(Flim-FliG界面)。

DESCRIPTION: The proposal seeks an understanding of the smallest biological motor known, the bacterial flagellar motor, which is widespread in both the eubacteria and the archaea. The motor has several distinctive features: (i) it is driven by the trans-membrane proton potential, not ATP; (ii) it undergoes true rotation; (iii) it can rotate in both the counterclockwise and clockwise directions, i.e., it has a switch; and (iv) the switch is controlled by the sensory transduction system to achieve chemotaxis. Thus the system permits exploration of several basic biological issues, such as sensory reception and transduction, controlled molecular switching, and electro-mechanical and osmo-mechanical energy transduction. The proposed research, to be carried out in Salmonella typhimurium, is basic in its nature. However, the information it has provided and will provide has been used by other researches working in more applied areas, which the role of motility and taxis in the virulence of microbial pathogens for humans (and other hosts including plants) and in environmental ecology (both on land and in the oceans) are under active investigation. The proposal makes heavy use of mutations (spontaneous and engineered) and or intergenic suppression, in the five proteins that comprise the motor. These are MotA, MotB, FliG, FliM, and FliN. It will build on existing knowledge concerning these proteins, with a view to identifying precisely the most critical regions and residues for (i) proton delivery to the site of torque generation (MotA and MotB); (ii) torque generation itself (the MotA-FliG interface); reception of sensory information by the switch (the CheY-FliM interface); and (iv) use of this information to switch motor direction (the FliM-FliG interface).